i think one of the things you're missing is that whole foods locations tend to be in more upscale, urban locations. and people that live in upscale, urban locations can't stand walmart.
But Walmart build pickup points at upscale neighbourhoods. They even built an automated store to do so, and it'd 20x80 foot, pretty small:
https://newsok.com/article/5551667/walmart-introduces-automa...